No Power...and Oil GS550E

[Uncle Fester]

Purchased a '78 GS550E and have been using it to commute 120 round trip a day in the northeast. Everything was fine until the other night @ 70mph, it felt like I was running out of fuel (power starting to drop off). It seemed a little early for reserve but not totally out of the question so, I switched to reserve and nothing. Sounded loud and throaty but revs continued to dip. Downshifted and revs came up but still not the normal power. Had a few miles to go till home so I rode her. At my exit, I looked down to see my left leg coated in oil. Oil light never came on. When coming to a stop. The bike died. Would re-start easily and with constant throttle, would stay running. In hindsight, it felt as though it wasn't running on all 4 but, where was the oil coming from? The oil level was not totally spent, and there's no mechanically sounds coming from the engine, indicating a lack of oil. Might it be a bad seal, blown headgasket, bad exhaust, etc.?

Also of note, the guy I bought the bike from indicated that there was only 10/30 in the bike and should be changed to 10/40. I was intending to do that this coming weekend In additon, the filler cap reads 10/40 yet my Hanes manual reads 20/50. Which is correct?

Any and all help is appreciated. I'm hoping this isn't catastrophic or expensive, as I bought the bike for $1,110 and was looking for inexpensive transpotation. Thank you.

Brian

[kalessin]

Do you have a repair manual yet?

How heavy was the oil distributed on your leg? What does your oil level look like right now (or how much did you add if you added oil after you got home?)

The oil light won't come on until almost too late, when there's not enough oil in the engine to make enough pressure on the sensor switch.

Driveway diagnosis: Wash the bike (don't spray too hard with the hose!), fill it up to the right level with oil, park it over a an old tarp or thick painter's dropcloth (easier cleanup), start it up and watch for where it's pushing out oil.

Common left-side oil leak places are from the following:
valve-cover gasket (and the half-moon plugs under the camshaft end plugs), head gasket, base gasket, shifter shaft, and the stator cover (the big round thing that sticks out the farthest

[Uncle Fester]

Actually appears to be coming from the front between 2-3 cylinder and lookes like it's from where the head bolts onto the cylinder.

[nabrams]

Do a compression check. If the valves are adjusted correctly and cylinders 2 or 3 have significantly lower compression than 1 & 2 then you might have blown the head gasket. If the compression is good then the leak might be coming from the valve cover and then dripping down to there. Take a good look.

[robinjo]

Sounds like a situation like I had with my S when I just got it. sparkplug on cylinder #1 went out so it lost power, I had to get home so continued to ride it, unburnt fuel/oil mixture was seeping out through the exhaust gasket coating the left side of the head and block, messy!

[Uncle Fester]

Robinjo,
I kind of was thinking the same thing, since it felt as though it wasn't running on all 4 but wasn't sure where the oil could have been coming from. I actually thought through the spark plug if it backed out a little and the fluid was getting by the rings?

What was the solution to your situation? New plug and a good cleaning?

[robinjo]

Robinjo,
I kind of was thinking the same thing, since it felt as though it wasn't running on all 4 but wasn't sure where the oil could have been coming from. I actually thought through the spark plug if it backed out a little and the fluid was getting by the rings?

What was the solution to your situation? New plug and a good cleaning?

I took out the spark plug and let it 'breathe' for a while, evaporating the gas in there afraid I would foul the new plug too. If it keeps fouling up you have either a too rich mixture problem or weak spark.

[nabrams]

I assume you've visually verified spark on all plugs. If not, do that first.
Then check compression.
One of those will tell the tale.
Until you you do both, you're just playing guessing games.